This invention relates to an apparatus for inspecting an internal circuit of a semiconductor device, and more particularly to an inspecting apparatus for locating or finding out the cause of a failure of an internal circuit of a semiconductor device.
Conventionally, an apparatus for inspecting an internal circuit of a semiconductor device has been used for locating the cause of a failure of a semiconductor device which was found not to meet manufacturing conditions at a development stage, returned because of being defective or found to be defective in a sampling inspection, to thereby improve the manufacturing process of a semiconductor device.
A conventional inspecting apparatus used for this purpose includes an inspection table which is provided with a U-shaped cutout and on which an inspection equipment such as a microscope, a positioner or the like, and a base on which the inspection table is mounted. The base is provided on a portion thereof positionally corresponding to the U-shaped cutout of the inspection table with a movable table, on which an IC socket is positioned for setting thereon a semiconductor device to be inspected. The IC socket is electrically connected through a cable to a tester for operating or examining the semiconductor device to be inspected and the positioner includes an inspection needle for directly probing the internal circuit of the semiconductor device, resulting in the cause of a failure of the semiconductor device being located.
In the conventional inspecting apparatus constructed as described above, the IC socket and tester are interconnected through the cable, resulting in being separated by a significant distance from each other. Unfortunately, this causes a true signal delivered from the tester to be significantly deteriorated through wirings of the IC socket, wirings of the tester or the cable, so that accurate inspection of the semiconductor device is failed or a function of the tester is deteriorated through the cable.
In order to solve the above-described problem, an approach that a semiconductor device to be inspected is set directly on the tester to reduce a length of the cable would be considered. However, such an approach causes any vibration or shock from an air fan of the tester, a floor and the like to be transmitted directly to the semiconductor device, to thereby render observation of the semiconductor device through a microscope highly difficult or substantially impossible. Further, when the inspection table is not provided with an effective vibration-proof structure, the vibration or shock is transmitted also to the inspection table or its peripheral equipments, to thereby cause the inspection needle of the positioner to be vibrated, leading to a failure in probing the semiconductor device.